Lauryl Sulfate Tryptose Broth. Selective Differential. Used to detect coliforms in H20. There is lactose in medium, which detects for Lac+ organisms by production of gas (differentiation). Na Lauryl Sulfate is selective agent (against noncoliforms)

Differential Medium that detects Deoxyribonuclease of Saureus. Medium contains DNA and toluidine. If the culture produces thermonuclease, then the nucleotides will react with toluidine, turning the medium from blue to red.